It is too cold today. The bear told the kitten that rubbing his hands would not be cold. He has already rubbed it.

A, all objects have internal energy, and the internal energy of snowman is not MINUS zero, so A is wrong;

B, the lower the temperature, the lower the snowman's internal energy, so B is wrong;

C, the snowman absorbs heat when it melts, and changes the internal energy through heat transfer, so C is wrong;

D, rubbing hands This is to change the internal energy by overcoming friction and doing work, so D is correct.

So choose D.